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Submission #224109

# Submission time Handle Problem Language Result Execution time Memory
224109 2020-04-17T08:09:57 Z oolimry Olympic Bus (JOI20_ho_t4) C++14
5 / 100
 102 ms 5360 KB 
#include <bits/stdc++.h>

using namespace std;
long long inf = (1LL << 56LL);

typedef pair<long long, long long> ii;
vector<ii> adj[205];
vector<ii> adjR[205];
long long dis[205];
long long dis1[205];
long long disn[205];
long long dis1R[205];
long long disnR[205];

int n, m; 

long long dij(int s, int t){
	fill(dis, dis + (n+3), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < adj[cur.second].size();j++){
            ii nei = adj[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

long long dijR(int s, int t){
	fill(dis, dis + (n+3), inf);
	
	priority_queue<ii, vector<ii>, greater<ii> > dtr; /// use greater<int>
	dtr.push(ii(0,s));
    dis[s] = 0;
    ///first is minpath, second is vertex
    while(!dtr.empty()){
        ii cur = dtr.top();
        dtr.pop();
        for(int j = 0;j < adjR[cur.second].size();j++){
            ii nei = adjR[cur.second][j];
            if(nei.first + cur.first < dis[nei.second]){
                dis[nei.second] = nei.first + cur.first;
                dtr.push(ii(dis[nei.second],nei.second));
            }
        }
    }
    return dis[t];
}

struct edge{
	long long u; long long v; long long c; long long d;
};
vector<edge> edges;

void prin(long long ans){
	if(ans >= inf) ans = -1;
	cout << ans;
	exit(0);
}

void subtask1(){
	long long ans = dij(1, n)+ dij(n, 1);
	for(int i = 0;i < m;i++){
		for(int i = 1;i <= n;i++) adj[i].clear();
		
		long long res = 0;
		for(int j = 0;j < m;j++){
			edge e = edges[j];
			if(i == j){
				adj[e.v].push_back(ii(e.c,e.u));
				res += e.d;
			}
			else adj[e.u].push_back(ii(e.c,e.v));
		}
		//cout << dij(1,n) + dij(n,1) + res << "\n";
		ans = min(ans, dij(1,n) + dij(n,1) + res);
	}
	
	prin(ans);
}

int main(){
	//freopen("i.txt","r",stdin);
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	cin >> n >> m;
	for(int i = 0;i < m;i++){
		long long u, v, c, d; cin >> u >> v >> c >> d;
		edges.push_back({u,v,c,d});
		adj[u].push_back(ii(c,v));
		adjR[v].push_back(ii(c,u));
	}
	
	if(m <= 1000) subtask1();
	
	dij(1,n);
	for(int i = 1;i <= n;i++) dis1[i] = dis[i];
	
	dij(n,1);
	for(int i = 1;i <= n;i++) disn[i] = dis[i];
	
	dijR(1,n);
	for(int i = 1;i <= n;i++) dis1R[i] = dis[i];
	
	dijR(n,1);
	for(int i = 1;i <= n;i++) disnR[i] = dis[i];
	
	long long ans = dis1[n] + disn[1];
	for(edge e : edges){
		ans = min(ans, e.d + dis1[n] + disn[e.v] + dis1R[e.u] + e.c);
		ans = min(ans, e.d + disn[1] + dis1[e.v] + disnR[e.u] + e.c);
	}
	
	prin(ans);
}

Compilation message

ho_t4.cpp: In function 'long long int dij(int, int)':
ho_t4.cpp:27:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0;j < adj[cur.second].size();j++){
                       ~~^~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp: In function 'long long int dijR(int, int)':
ho_t4.cpp:48:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0;j < adjR[cur.second].size();j++){
                       ~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 48 ms 512 KB Output is correct
2 Correct 5 ms 436 KB Output is correct
3 Correct 67 ms 512 KB Output is correct
4 Correct 74 ms 512 KB Output is correct
5 Correct 37 ms 508 KB Output is correct
6 Correct 6 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 18 ms 512 KB Output is correct
10 Correct 102 ms 512 KB Output is correct
11 Correct 101 ms 512 KB Output is correct
12 Correct 100 ms 632 KB Output is correct
13 Correct 41 ms 512 KB Output is correct
14 Correct 51 ms 512 KB Output is correct
15 Correct 47 ms 512 KB Output is correct
16 Correct 52 ms 512 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 4712 KB Output is correct
2 Correct 34 ms 4840 KB Output is correct
3 Correct 31 ms 4968 KB Output is correct
4 Correct 6 ms 512 KB Output is correct
5 Correct 46 ms 540 KB Output is correct
6 Correct 9 ms 384 KB Output is correct
7 Correct 9 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Incorrect 31 ms 4848 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 48 ms 512 KB Output is correct
2 Correct 7 ms 384 KB Output is correct
3 Correct 25 ms 4340 KB Output is correct
4 Correct 6 ms 384 KB Output is correct
5 Correct 29 ms 4712 KB Output is correct
6 Correct 5 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Incorrect 30 ms 5360 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 48 ms 512 KB Output is correct
2 Correct 5 ms 436 KB Output is correct
3 Correct 67 ms 512 KB Output is correct
4 Correct 74 ms 512 KB Output is correct
5 Correct 37 ms 508 KB Output is correct
6 Correct 6 ms 384 KB Output is correct
7 Correct 5 ms 384 KB Output is correct
8 Correct 5 ms 384 KB Output is correct
9 Correct 18 ms 512 KB Output is correct
10 Correct 102 ms 512 KB Output is correct
11 Correct 101 ms 512 KB Output is correct
12 Correct 100 ms 632 KB Output is correct
13 Correct 41 ms 512 KB Output is correct
14 Correct 51 ms 512 KB Output is correct
15 Correct 47 ms 512 KB Output is correct
16 Correct 52 ms 512 KB Output is correct
17 Correct 31 ms 4712 KB Output is correct
18 Correct 34 ms 4840 KB Output is correct
19 Correct 31 ms 4968 KB Output is correct
20 Correct 6 ms 512 KB Output is correct
21 Correct 46 ms 540 KB Output is correct
22 Correct 9 ms 384 KB Output is correct
23 Correct 9 ms 384 KB Output is correct
24 Correct 5 ms 384 KB Output is correct
25 Incorrect 31 ms 4848 KB Output isn't correct
26 Halted 0 ms 0 KB -